The English translation of the Bhikkhu-vibhanga: the first part of the Suttavibhanga, which itself is the first book of the Pali Vinaya Pitaka, one of the three major ‘baskets’ of Therevada canonical literature. It is a collection of rules for Buddhist monks.
The English translation of the Vinaya-pitaka (first part, bhikkhu-vibhanga) contains many...

Monks’ Expiation (Pācittiya) 25

Bu-Pc.25.1.1BD.2.282 … at Sāvatthī in the Jeta Grove in Anāthapiṇḍika’s monastery. Now at that time a monk was walking for alms in Sāvatthī along a certain road. And a nun was walking for alms along that road. Then that monk spoke thus to that nun: “Go, sister, in such and such a place alms-food is being given.” And she spoke thus: “Go, master, in such and such a place alms-food is being given.”

These had become friends through constantly seeing (one another). Now at that time robe-material was being distributed to the Order. Then that nun, going for exhortation, approached that monk, and having approached and greeted that monk, she stood at a respectful distance. As she was standing at a respectful distance, that monk spoke thus to that nun:

“Sister, this is my share of the robe-material, you may accept it.”

“Yes, master, my robe is worn thin.” Then that monk gave that nun the robe-material. Then that monk became one whose robe was worn thin. Monks spoke thus to this monk.

“Your reverence, make up your robe-material now.” Then that monk told this matter to the monks. Those who were modest monks … spread it about, saying:

“How can a monk give robe-material to a nun?” …

“Is it true, as is said, that you, monk, gave robe-material to a nun?”

“It is true, lord.”

“Is she a relation of yours, monk, or not a relation?”

“She is not a relation, lord,” he said.

“Foolish man, one who is not a relation does not know what is suitable or what is unsuitable, or what BD.2.283 is right or what is wrong for a nun who is not a relation.[1] How can you, foolish man, give robe-material to a nun who is not a relation? It is not, foolish man, for pleasing those who are not (yet) pleased … And thus, monks, this rule of training should be set forth:

“Whatever monk should give robe-material to a nun who is not a relation, there is an offence of expiation.”

And thus this rule of training for monks came to be laid down by the lord.

Bu-Pc.25.2.1 Then scrupulous monks did not give robe-material in exchange to nuns.[2] The nuns … spread it about, saying:

“How can the masters not give robe-material to us in exchange?” Vin.4.60

Monks heard these nuns who … spread it about. Then these monks told this matter to the lord. Then the lord on this occasion, in this connection, having given reasoned talk addressed the monks, saying:

“Monks, I allow you to give in exchange to five (classes of people): to a monk, a nun, a female probationer, a male novice, a female novice. I allow you, monks, to give in exchange to these five (classes of people). And thus, monks, this rule of training should be set forth:

“Whatever monk should give robe-material to a nun who is not a relation, except in exchange, there is an offence of expiation.”[3]

Robe-material means: any one robe-material of the six (kinds of) robe-materials, (including) the least one fit for assignment.[5]

Except in exchange means: setting aside (the fact that) he gives in exchange, there is an offence of expiation.

Bu-Pc.25.3.2 If he thinks that she is not a relation when she is not a relation, (and) gives robe-material (to her), except in exchange, there is an offence of expiation. If he is in doubt as to whether she is a relation … If he thinks that she is a relation when she is not a relation … there is an offence of expiation. If he gives robe-material to one ordained by one (Order only), except in exchange, there is an offence of wrong-doing. If he thinks that she is not a relation when she is a relation, there is an offence of wrong-doing. If he is in doubt as to whether she is a relation, there is an offence of wrong-doing. If he thinks that she is a relation when she is a relation, there is no offence.

Bu-Pc.25.3.3 There is no offence if she is a relation; if there is an exchange; if there is a large thing for a small thing, or a small thing for a large thing; if a nun takes it on trust; if she takes it for the time being; if he gives another requisite, except robe-material; if she is a female probationer, a female novice; if he is mad, if he is the first wrong-doer.[6]